Powder train interrupter



- ?atented Feb. 19, 1952 assess? Sacob Babinow, Washington, D. G, assignor to the United States of America as represented by the Secretary of the Navy Application November 13, 1943, Serial No. 510,239

' 2 en. (en. 102-78) This invention relates to an inertia-operated powder train interrupter for use in projectiles, and more particularly to a device wherein an explosion discharge passage remains blocked until the projectile has traveled a safe distance away from the gun, at which time a communicating passage is established between a squib and a booster charge.

One object of this invention is to provide a device for positively maintaining a passage connecting a squib and a booster charge in closed conditionuntil the projectile containing the device is fired from a gun and the device is acted upon by setback. Upon firing of the projectile, after a delay which is interposed for purposes of safety, a connecting discharge passage is established between the squib and the booster charge, thus arming the device.

A further object of this invention is to provide a device of the character described which cannot be accidentally armed by dropping or jolting and which operates only after actuation by a sustained force of setback and substantial cessation of the force of setback.

A further object of this invention is to provide a device of the character described which is simple in operation and manufacture, and positive in action.

These and other objects of the invention will be apparent from the following description and the attached drawings in which:

Fig. l is a vertical sectional view of one form -of the device showing the parts in their initial unarmed positions;

Fig. 2 is a vertical sectional view similar to Fig.

member, and near the upper end of the base member, its inner diameter is enlarged to form shoulder i2. A thin-walled cylindrical casing I3 is positioned on the upper end of base member m. A support It, having a cylindrical base portion l5, rests on shoulder l2 and is held in position by screw [50, the upper portion of the support having a cross-section as shown in Fig. 3. Support It has a squib receiving cavity IS in its lower portion which is connected by passage I! to the lower surface of the support. Passage I1 is positioned soas to lie directly over the opening II in base member III. The base l5 of the support has a longitudinal passage [8 extending therethrough. A shaft l9 extends upwardly from the center of base member Ill and is held in place l but taken in a plane-at right angles thereto;

Fig. 3 is a cross-sectional view taken on lines 3-3 of Fig. 1;

Fig. 4 is a view similar. to Fig. 1 but showing only a portion of the device with the parts in their immediate positions;

Fig. 5 is a view similar to Fig. 4 but with the parts in their final armed positions; and

Fig. 6 is a perspective view of most of the moving parts of the device in their initial positions.

In the drawings, the device comprises a cupshaped lower base member l0 which is extern'ally threaded at its lower end for mounting on other parts of the fuze. A passage H extends longitudinally through the closed end of the base by screw 20, the shaft projecting through the center of the lower portion I 5 of the support and being held therein by a screw 2 I.

A cylindrical rotor 22 is rotatably mounted on shaft 19in base member ID and has a longitudinal passage 23 extending therethrough and so positioned as to connect passages l1 and II when the rotor is rotated to its armed position. A spring 24 mounted on shaft I9 is attached to a screw 25 on the bottom of support l5 and tends to rotate the rotor to a position in which the passages i1, 23 and II are aligned. The rotor also has a recess 26 in its upper surface.

On the upper surface of base It of the support is an inverted U-shaped guide 21 having an opening in its upper portion and attached by 'meansof'screws 28 and 28a to base IS. A pin 29 carrying a weight 30 extends upwardly a short distance through the opening in member 21 and extendsdownwardly through passage l8 in support l5 and into recess 26 in the upper surface of the rotor, thus holding the rotor against rotation. A spring 3| bearing against the weight 30 and the upper surface of support I 5 tends to push pin 29 upwardly out of the recess 26 in the rotor.

Near the upper end of support l4, a shaft 32 is mounted so as to extend in a'transverse direction-into the space between the support and casing l3. Shaft 32 supports a member which comattachedat one end to a post 38 on support l4. and at its other end is keyed to thecam member 33, the spring tending to rotate inertia ele- 32 and has rotatably mounted thereon an inertia element 42 which is keyed to one end of a spring 43, the other end of which is attached'to a post 44 on'support l4. Spring 43 tends to rotateelement 42 in a counterclockwise direction. flange 45 extends inwardly toward support H from a portion of the periphery of element 42 so as to interlock at the proper time, as will be explained below, with flange .31 and shoulder 40 on member 34. A resilient latch 48 which extends upwardly adjacent member 41 is mounted on the up er surface of support I! bymeans of screw 28a.

In operation, the parts of the device before acceleration are in the positions shown in Figs. 1 and 2. Due to the fact that the-passage 23 in rotor 22 is not in alignment with passages l1 and ll,'flring of the squib (not shown) in cavity It will not detonate the boostercharge Flanges 31 and as are located on the as the acceleration oi the device ceases sufllcicntly for the spring 3'! to rotate the element 34. The latter is thus rotated to the position shown in Fig. 5 where it is halted in its rotation byengasement with post '38. I

Cam 33, which rotates with element 84, retains pin 2! in its blocking position until element 34 reaches the position shown in Fig. 5, at which time the cam has rotated out of the way of the upper end of pin 2!, and spring ll then pushes the pin upwardly out of the opening 24 in rotor 21, thus allowing spring 24 to rotate the rotor to the position wherein openings I1. 23 and II are aligned and the device is armed. The armed position of rotor fl'maybe deflned by detents or other suitable means.

During the acceleration of the device, the

weight it on pin 29 is forced downwardly by the a force of setback, thus moving pin 29 downwardly away from cam 31 so as to prevent friction beward movement of pin 29 also doubly assures that (not shown) to which passage ll leads, and,

therefore. the device is unarmed. The rotor 22 is retained in its unarmed position by pin I9 which extends into recess -26 in the rotor, the pin being held against upward movement out of openin 28 by cam 33 against which the upper end of the pin is urged by spring II. The relative positions of the pin and the cam may be seen more clearly in Fig. 6. Inertia element 84 is ur ed in a counterclockwise direction by spring 15 but is unable to move in that direction, due to the fact that shoulder 40 of member 34 engages the end of flange on member 42. Member 4! is at the limit of its counterclockwise rotation due to the fact that it abuts post 44, and its clockwise rotation is prevented by its flange 45 contacting flange 31 of member I4.

when the device is accelerated in the direction of the arrow in-Fig. 1, due to flring a projectile containing it, elements 42 and 34 both tend to rotate in a clockwise direction under the actuation of the force of setback, but since member 42 is initially held against clockwise rotation by engagement of its flange 45 with the flange 31 of element 34, only inertia element 34 initially is able to rotate in a clockwise direction. As soon as element 34 rotates under the force of setback to the position in which it is shown in Fig. 4. wherein its rotation is halted by contact with post 36, opening 39 is positioned adjacent the end of flange 45 on element 42 so as to permit rotation of element 42 in a clockwise direction. As soon as element 42 is free to rotate in a clockwise direction, it moves to the chain line position shown in Fig. 4 so that for a short period of time while the acceleration continues, both elements 34 and 42 are at the limits of their clockwise rotation. I

As soon as the acceleration decreases sufllciently, the spring 43 rotates member 42 in a counterclockwise direction, the rotation being halted by engagement of element 42 with a projection on the spring latch member 48 whereby member 42 is retained in the position shown in Fig. 5. Since flange 45 is no longer in the path of shoulder 40 of element 44, the latter is free to rotate in a counterclockwise direction as soon it will retain the rotor 22 against rotation during acceleration of the device.

Due to the interlocking arrangement involving the flanges on theinertia elements 42 and 44. the device is safe against unsustained accelerations caused by droppingor jolting, and such minor accelerations wfll not have a cumulative effect due to the fact that spring Iii will return element 34- to its initial position after the unsustained acceleration is terminated. In order to arm the device, the acceleration must be powerful and sustained, for it must move element 34 to its "position shown in Fig. 4 and must continue long enough thereafter to move element 42 to its position shown in Fig. 4.

I claim:

1. In an inertia-operated arming device, an element rotatable from an unarmed to an armed position and having an explosion discharge passage, said passage being inoperative when said element is in its unarmed position, biasing means tending to cause rotation of said element to its armed position, a pin normally engaging said rotatable element to retain said element in its unarmed position, biasing means tending to move said pin out of engagement with said rotatable element, a cam normally retaining said pin in engagement with said rotatable element, biasing means tending to move said cam for'disengagement of the pin from said rotatable element. means for holding said cam in engagement with said pin comprising a flanged inertia element movable with said cam, and a second inertia element having a flange adapted to engage a flange of said first inertia element, sustained acceleration of the device and substantial cessation of said acceleration causing movement of said cam for disengagement of said pin from said rotating element, whereby said rotating element is free to move to its armed position.

2. In an inertia-operated arming device which is normally unarmed, a support, a, first spring biased inertia mass pivoted to said support for controlling the arming of said device and carrying a first circumferential flange section with a radially inward projection at one end, a second spring biased inertia mass pivoted to said support at a point spaced from said first mass and carrying a second circumferential flange section, said projection on said first flange co-acting with said second flange to maintain said masses in normal unarmed position, said first and second flanges mew? oo-aoting upon setback to allow said first mess to rotate before said second mass, and said spring bias for seid first mess operative after rotation of said second ss to reverse rotation of said first mess to a position permitting arming of said device.

JACOB f: A INOW.

REFERENCES SWEEP Number Number i-= STATES PA w:

Name Dete Moren Oct. 1, 1918 Rogers June e, 1929 Mathsen Sept. 17, 1935 Mathsen Feb. 2, 1937 Junghams Sept. 20, 1938 Junghens July 25, 1939 Horan Nov. 13. 1915 FOREIGN PATENTS Country Date Germany Oct. 13, 1919 Great Britein Aug. 27, 1926 

